When a game is in development, some ideas are cut and some make it to the final release. That means we might catch glimpses of ideas or content that never make the final cut. Luigi's Mansion had quite a considerable amount of ideas that were scrapped or changed for the final release, and as you can see above, some fans are coming together to try and restore that content. Certainly an interesting project, and one I hope Nintendo doesn't squash! Thanks to Ultimate_Litten for the heads up!